1. Field of the Invention
This invention relates to a method of making a printing hammer unit having a plurality of printing hammers secured together, and, more particularly, to a printing hammer unit having a plurality of printing hammers held by resilient members.
2. Description of Prior Arts
There has been widely known a printer of a type, in which a character wheel or belt having characters arranged therearound or thereon is rotated or moved, and the characters on the character wheel or belt are impacted by printing hammers on recording paper interposed between the character holding member and the printing hammers to thereby record the characters on the recording paper.
Further, a printer having such hammers held by springs studded on a base has already been proposed by the applicant in U.S. application Ser. No. 565,225.
In these printers, a plurality of printing hammers must be disposed in juxtaposed relationship when printing is to be effected in a plurality of columns. The plurality of printing hammers so used must have a uniform hammer movement characteristic (or stroke) so as to secure uniform concentration and fixed position of the printed characters from line to line. It is also desirable that such a group of hammers be easily and accurately set. Particularly, in the printers of the above-described type, wherein the printing hammers are held by springs, it is preferable that the spring to drive each printing hammer has a uniform resiliency to secure uniform printing strokes.